The Hughes 500C helicopter with its right-rear door removed spirals downward in dizzying arcs from 1,500 feet, but inside Robert Cameron goes about his business with his usual methodical calm. He dangles a 15-pound camera rig from one hand, checks his safety harness with the other, then leans through the open doorway until he is stretched out almost horizontally. At his hand signal, the chopper heels over to a stomach-wrenching 60-degree angle and plummets straight down like a runaway elevator. Cameron pays no attention to the G-force that's doubling his 185-lb. body weight or the air rushing past him and composes precisely the picture he wants. Click, click, click. "Got it," he calls into his mike, and his pilot rights the helicopter and zooms off toward the horizon.

Aerial photography is ordinarily a job for the young and the rash. But at 77—that's right, 77—Cameron is the oldest, and many think the best, in the business. Bundled up against the chill of windblast, he has leaned out of blimps, balloons, gliders, choppers and high-wing Cessnas to get his shots. "I've flown hundreds of photographers," says helicopter pilot Jim Larsen, who often takes Cameron aloft. "Bob is the grand master. Imagine standing on a spinning platform trying to compose a picture, balance the light and look through the viewfinder all at the same time—without getting nauseous. Eight out of 10 professionals can't do that, let alone match the photos that Bob gets."

The best of what Cameron gets can be seen in eight oversize (11" x 14") volumes of stunning, full-color, bird's-eye panoramas of famous cities and landscapes, starting in 1969 with Above San Francisco. Cameron's latest offering, Above New York (introduction by George Plimpton, text by New York Times architectural critic Paul Goldberger), reached bookstores in September. Over the years, his Above series has also taken him over Yosemite, London (with Alistair Cooke), Paris (with Pierre Salinger), Los Angeles, Hawaii and Washington, D.C.

Airborne derring-do aside, Cameron is also a daring entrepreneur: As chairman of Cameron and Co., he is his own publisher, and his books now require an upfront investment of $700,000 each, mainly in printing and binding costs. "Nobody takes a crapshoot like that except a crazy guy like me," he says. Well, not all that crazy. Collectively, his Aboves have sold more than 1.3 million copies. All are still in print, and they gross a steady $1 million-plus a year.

Cameron was certainly not known as a risk taker in his younger years. A native of Des Moines, he married his childhood sweetheart, Janet Elliott, in 1932, his freshman year at the University of Iowa. Two years later, the Depression forced him to abandon college to earn a living at the Des Moines Register & Tribune, where he learned photography on the job. Exempt from the draft in World War II because of an intestinal disorder, Cameron went to work as a civilian employee of the War Department. There he was introduced to aerial photography and spent four years documenting the construction of U.S. military bases.

To support his family of four, Cameron put aside his camera after the war and joined the New York franchise of a French cosmetics firm, eventually becoming its president. After 14 years, he wearied of the daily commute from the suburbs, sold his share of the company to a partner and moved with his family to San Francisco to do he-wasn't-quite-sure-what.

There were false starts. A wine connoisseur, Cameron designed a cork ejector but found the market for his invention limited. In 1964, after losing 15 pounds on a low-carbohydrate diet devised by a friend, Cameron self-published a slender volume with a catchy title: The Drinking Man's Diet. "We ended up selling 2.4 million copies," he boasts, before complaints from nutritionists (who felt the diet was too high in fat and protein) persuaded him to halt printing. By then, he had a nice cash reserve under his tightened belt. An avid golfer, he could have begun a serene retirement.

Instead, mostly for the fun of it, he returned to aerial photography at the age of 54. Notes Cameron: "For most of us, looking down at things—'This is where I live' or 'That is my office building'—has great appeal. And with photos, you can look as long as you want." He showed his work to friends, who encouraged him to publish. Above San Francisco came out just before Christmas in 1969, and the book sold out so quickly that Cameron knew his golf game would be taking a backseat for some time.

To shoot Above New York, Cameron logged 35 flight hours over the city during a 14-month span. His favorite shooting altitude is 1,000 feet, low enough to capture architectural details and high enough for perspective. "We've had aerial photography before Bob Cameron, and we will have it after him," says Paul Goldberger, "but he's the first to recognize the spectacular possibilities of looking at great cities in depth from on high." The public agrees. Cameron's one-man show of photographs from Above Paris at that city's Bibliothèque Historique sold more tickets than any other exhibit in the museum's history. Last January, as a result, he received Paris' distinguished Medaille de Vermeil.

Cameron has had his scrapes and close calls. When he hovered too long over the opening parade at England's Ascot races 10 years ago, no less a personage than the Duke of Edinburgh telephoned police to complain. Once, during Richard Nixon's Presidency, Cameron flew low along the Pacific coast to get a photo titled "Lone Figure on the Beach at San Clemente," and a Marine chopper was scrambled to shoo him away. His closest shave came over Los Angeles when he discovered that his safety harness was working loose—fortunately, only after he was safely back inside the helicopter.

As he contemplates new sorties over Chicago and Rome, Cameron remains philosophical about occupational hazards that most septuagenarians wouldn't dream of facing. "I feel great, why shouldn't I keep doing this?" he says with a shrug. "Nothing makes me happier. And when my time comes, I guess falling out of a helicopter would be as good a way to go as any. I'm just not going to rush it."